1、 再給第三個例子（后臺數(shù)據(jù)庫分頁）

<display:table class="data" cellpadding="0"

requestURI="/NetXpert/room/idcRoomShelfAction.do?actionType=doListIdcShelf" cellspacing="0" style="width:98%" name="shelfs" >

…… ……

</display:table>

從該例中可看出：

1）,、table只設(shè)置了requestURI屬性,，沒有設(shè)置pagesize屬性，由requestURI指定的url來完成分頁功能

2）,、IdcRoomShelfAction.java中的相關(guān)函數(shù)的代碼（紅色部分的代碼完成了分頁）：

public ActionForward doListIdcShelf(ActionMapping mapping, ActionForm form,

HttpServletRequest request, HttpServletResponse response) {

int page = 1; // 默認(rèn)值：第1頁

PaginatedListHelper paginaredList = new PaginatedListHelper();

// 獲取頁號

if (request.getParameter("page") != null

&& !"".equals(request.getParameter("page"))) {

page = Integer.parseInt(request.getParameter("page"));

}

paginaredList.setObjectsPerPage(20); // 默認(rèn)每頁顯示15條記錄,，可以重新賦值

paginaredList.setPageNumber(page); // 設(shè)置頁號

ArrayList voList = new IdcRoomShelfBo().selectShelf();

ArrayList formList = ((IdcRoomShelfForm) form)

.getFormListFromVOList(voList);

paginaredList.setFullListSize(formList.size()); // 記錄總數(shù)

paginaredList.setList(formList); // 全部的數(shù)據(jù)集

paginaredList.getCurrentPageRecord(); // 獲取當(dāng)前頁號需要的數(shù)據(jù)集

request.setAttribute("shelfs", paginaredList);

return mapping.findForward("shelfList");

}

3）、分頁類的代碼：（display1.1的發(fā)布已經(jīng)能夠支持后臺數(shù)據(jù)庫分頁,，但必須實現(xiàn)其提供的PaginatedList接口）

package com.asiainfo.idc.room.util;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

//PaginatedList和SortOrderEnum為displaytag-1.1.1.jar提供的jar包中提供的類

import org.displaytag.pagination.PaginatedList;

import org.displaytag.properties.SortOrderEnum;

/**

* 針對displaytag標(biāo)簽擴(kuò)展的后臺分頁功能

* @author lvping

*/

public class PaginatedListHelper implements PaginatedList {

private List list; // 數(shù)據(jù)集

private int pageNumber = 1;// 頁號

private int objectsPerPage = 15;// 每頁顯示的記錄數(shù)

private int fullListSize = 0;// 全部記錄數(shù)

private String sortCriterion;

private SortOrderEnum sortDirection;

private String searchId;

public List getList() {

return list;

}

public void setList(List list) {

this.list = list;

}

public int getPageNumber() {

return pageNumber;

}

public void setPageNumber(int pageNumber) {

this.pageNumber = pageNumber;

}

public int getObjectsPerPage() {

return objectsPerPage;

}

public void setObjectsPerPage(int objectsPerPage) {

this.objectsPerPage = objectsPerPage;

}

public int getFullListSize() {

return fullListSize;

}

public void setFullListSize(int fullListSize) {

this.fullListSize = fullListSize;

}

public String getSortCriterion() {

return sortCriterion;

}

public void setSortCriterion(String sortCriterion) {

this.sortCriterion = sortCriterion;

}

public SortOrderEnum getSortDirection() {

return sortDirection;

}

public void setSortDirection(SortOrderEnum sortDirection) {

this.sortDirection = sortDirection;

}

public String getSearchId() {

return searchId;

}

public void setSearchId(String searchId) {

this.searchId = searchId;

}

/**

* 根據(jù)總的數(shù)據(jù)集和每頁需要的首記錄,、尾記錄索引，從總記錄集中得到需要的記錄集

* 這是一個取巧的分頁方法,，并非真正的根據(jù)每頁請求拼sql進(jìn)行查詢,，而是對于整個數(shù)據(jù)查詢的結(jié)果從中取各頁需要的數(shù)據(jù)集合，對于超大數(shù)據(jù)量的查詢效率可能不會太高

*/

public void getCurrentPageRecord() {

ArrayList v = new ArrayList();

Iterator iterator = null;

try {

if (this.getList() != null) {

iterator = this.getList().iterator();

int i = 0;

int fromRow = 0;

int toRow = 0;

if (this.getPageNumber() == 1) { // 首頁

fromRow = 1; // 從第一行開始

toRow = this.getObjectsPerPage();

} else {

fromRow = (this.getPageNumber() - 1)

* this.getObjectsPerPage() + 1;

toRow = fromRow + this.getObjectsPerPage();

}

if (toRow > this.getFullListSize()) // 如果尾行數(shù)超過list的大小

toRow = this.getFullListSize();

while (iterator.hasNext()) {

i++;

if (i < fromRow) {

iterator.next();

continue;

} else if (i > toRow) {

iterator.next();

continue;

} else {

v.add(iterator.next());

}

}

this.setList(v);

}

} catch (Exception ex) {

ex.printStackTrace();

}

}

}

 Displaytag用法整理三